1. Field of the Invention
The present invention relates to a projection zoom lens and a projection type display device, and for example, to a projection zoom lens suitable for enlarging and projecting a light beam that carries video information from a light valve onto a screen and a projection type display device including this lens.
2. Description of the Related Art
Conventionally, projection type projector devices (projection type display devices) that utilize a light valve, such as liquid crystal display elements, DMD's (Digital Micromirror Device: registered trademark), or the like, have been commonly available. In recent years, presentations using such projection type display devices have been popularly performed as a result of the rapid progress of miniaturization and high definition of light valves as well as the spread of personal computers. Under these circumstances, the demand for compact projection type display devices which have a superior portability while having excellent projection performance is increasing, and accordingly projection lenses are being expected to be configured to be compact while keeping high performance. With increasing competition in development, more cost reduction is becoming strongly desired, in addition to the above demands.
Known projection lenses having a compact configuration, which can be used for the projection type display devices, include lens systems which substantially consists of two lens groups: a first lens group having negative refractive power and a second lens group having positive refractive power are arranged in this order from the magnification side and which are composed of five lenses in total, as disclosed in Japanese Unexamined Patent Publication No. 2008-107798 and Japanese Unexamined Patent Publication No. 2010-113150, for example.